The present invention relates to a system and method for steering a wheeled vehicle such as an automobile, and more specifically to a rear wheel steering control system and method which are arranged to reduce the steering amount of rear wheels especially when vehicle speed is low.
A rear wheel steering system of a conventional type is arranged to steer the rear wheels a large amount in a direction opposite to the direction in which the front wheels are steered in order to reduce the turning radius of the vehicle when the vehicle speed is low or when the steering amount of the front wheels is large, and to steer the rear wheels to a relatively small extent in the same direction as the front wheels in order to improve the direction control and stability of the vehicle when the vehicle speed is high or when the steering amount of the front wheels is small. In this system, if the front wheels are steered in order to move the vehicle out of a narrow parking space while the vehicle speed is low or zero, then the rear wheels are also steered in the opposite direction to the steered direction of the front wheels. Accordingly, the outside rear wheel moves outwardly along a solid line curve shown in FIG. 1 in contrast with a broken line curve obtained when the rear wheels are not steerable, and therefore the rear of the vehicle may bump against an adjacent object such as a side wall of a garage or a next automobile.